CGAL users discussion list

[Adam Getchell <>]

Hello all,

I’m attempting to implement the (2,6) move which may be described pictorially as:

However, it appears that once I insert a new vertex (v_center), the triangulation is re-calculated without taking into account the new cells and neighbors that I create in the following code (starting on line 207) of https://github.com/acgetchell/CDT-plusplus/blob/master/src/S3ErgodicMoves.h 

When I run unit tests, I consistently get:

┌─[adam][Hapkido][±][master ✓][~/CDT-plusplus]

└─▪ ./build/unittests --gtest_filter=S3ErgodicMoves.MakeA26Move 

Note: Google Test filter = S3ErgodicMoves.MakeA26Move

[==========] Running 1 test from 1 test case.

[----------] Global test environment set-up.

[----------] 1 test from S3ErgodicMoves

[ RUN      ] S3ErgodicMoves.MakeA26Move

Generating universe ...

Pass #1

Fixing foliation....

Pass #2

Fixing foliation....

Pass #3

Fixing foliation....

Pass #4

Fixing foliation....

Pass #5

Fixing foliation....

Pass #6

Fixing foliation....

Pass #7

Fixing foliation....

Classifying simplices....

Valid foliation: true

Delaunay triangulation has 96874 cells.

There are 30144 (3,1) simplices and 36291 (2,2) simplices and 30439 (1,3) simplices.

Number of vertices before = 15268

Random number is 1272

Neighbor 0 is of type 31

Neighbor 1 is of type 22

Neighbor 2 is of type 13

Neighbor 3 is of type 13

(1,3) simplex 1272 is movable.

The neighboring simplex 0 is of type 31

Vertex index 1 is 1 with coordinates of -3.05843 1.64532 1.98468

Vertex index 2 is 2 with coordinates of -2.90759 2.10945 1.75958

Vertex index 3 is 3 with coordinates of -3.10277 2.03405 1.49515

Vertex v_bottom is 0 with coordinates of -2.33325 1.26426 1.39913

Vertex v_top is 0 with coordinates of -3.86226 2.33575 2.15109

Average x-coord is -3.02293

Average y-coord is 1.92961

Average z-coord is 1.74647

Timeslice is 4

Inserted vertex -3.02293 1.92961 1.74647 with timeslice 4

Number of vertices after = 15269

Classifying simplices....

../unittests/S3ErgodicMovesTest.cpp:185: Failure

Value of: T.tds().is_valid()

  Actual: false

Expected: true

Triangulation is invalid.

../unittests/S3ErgodicMovesTest.cpp:197: Failure

Value of: N3_31_after

Expected: is equal to 30146

  Actual: 30149 (of type unsigned long)

(3,1) simplices did not increase by 2.

../unittests/S3ErgodicMovesTest.cpp:200: Failure

Value of: N3_22_after

Expected: is equal to 36291

  Actual: 36287 (of type unsigned long)

(2,2) simplices changed.

../unittests/S3ErgodicMovesTest.cpp:203: Failure

Value of: N3_13_after

Expected: is equal to 30441

  Actual: 30444 (of type unsigned long)

(1,3) simplices did not increase by 2.

[  FAILED  ] S3ErgodicMoves.MakeA26Move (2064 ms)

[----------] 1 test from S3ErgodicMoves (2064 ms total)

[----------] Global test environment tear-down

[==========] 1 test from 1 test case ran. (2064 ms total)

[  PASSED  ] 0 tests.

[  FAILED  ] 1 test, listed below:

[  FAILED  ] S3ErgodicMoves.MakeA26Move

 1 FAILED TEST

My questions:

1. Is it correct to delete the two old cells before creating the new ones?

2. Is there a way to create a vertex without inserting it into the Delaunay triangulation?

3. If not, is there a way to prevent the Delaunay triangulation from re-triangulating with the newly inserted vertex before other operations are created?

4. What is the correct way to create new cells in a region with older ones?

5. How do I know that I need to change orientation (e.g. line 2097 in https://github.com/CGAL/cgal/blob/master/Triangulation_3/include/CGAL/Triangulation_data_structure_3.h )?

Thanks for any advice!

Adam Getchell
about.me/adamgetchell